From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH 2/2] Fix console handling during suspend/resume Date: Fri, 16 Jun 2006 15:56:52 +0200 Message-ID: <20060616135652.GE1666@elf.ucw.cz> References: <20060614103404.GC28536@elf.ucw.cz> <200606141846.55839.david-b@pacbell.net> <20060615084153.GC9423@elf.ucw.cz> <200606150957.42449.david-b@pacbell.net> <20060615180350.GG23859@elf.ucw.cz> <20060615191925.GA1849@elf.ucw.cz> <1150421189.7725.81.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: Linus Torvalds Cc: David Brownell , linux-pm@lists.osdl.org List-Id: linux-pm@vger.kernel.org Hi! > > Well, solving that problem is exactly why we have the PM callbacks in > > bus hierarchy. > = > No. That's a separate thing. = > = > We have PM callbacks in the bus hierarchy because we need that just to = > turn them off. You can't turn off the device after you've turned off the = > bus it is attached to. > = > But that's _totally_ orthogonal to the issue that a complex state save ma= y = > need a totally unrelated device - along dependancies we don't even _know_. > = > For example, when a device save needs to allocate memory, that in turn ca= n = > end up needing to write to just about _any_ device - and there simply _is= _ = > no hierarchy for that. No such hierarchy is even possible, because it's a = > circular problem. > = > Btw, one final note: > = > If people who do STD really do want to suspend all devices and then wake = > up devices that lead to the STD device, in the end, I personally simply = > don't care. No, this is not what I want. I want to: * freeze all devices (can be implemented as suspend) * create atomic image * unfreeze all devices (can be implemented as resume) * write image to disk * powerdown (which implies suspending devices). ...in fact, that is what we do today. Pavel -- = (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html